Foreclosure Radar and any other 3rd party sources pretty much simply post whatever is recorded regardless of whether it is a first, second or any other sort of lien on a home. So if it has been recorded it should show up. Also only the initial amounts are available.
Cancellations/postponements are always frustrating. When we were going downtown to the auctions most all of the properties would be postponed for some reason. However the postponements would not be announced until the actual day of the auction in most cases. Sometimes they get announced a day or a few days earlier but most did not. The info generally shows up on the site like fidelityasap or other like sites.